Efficiency of slow release fertilizers on reducing the rates of mineral-N fertilizers in Flame seedless vineyards

Abstract

This study was conducted during 2021, 2022 and 2023 seasons on 8 years old Flame Seedless vineyard. The vines were grown in Aiat vineyard for grapes production located in Luxor Governorate, Egypt. The perleka a slow release fertilizer, was used as a totally or partial replacement of the fast mineral N release fertilizer. The experiment was set up as a complete randomized block design. The results revealed that using the recommended dose of nitrogen (RDN) via 25% as a mineral source and 50% slow release or 60 to 80% slow release significantly increased the wood pruning weight and leaf area as well as their of total chlorophylls, N, P and K contents compared to use the RDN only as a fast mineral N fertilizer. Using 80% of RDN via slow release significantly stimulated these traits more than other used treatments. No significant differences were seen due to fertilize by either 80 or 60% slow release as well as 25% mineral plus 50% slow release fertilizer. Moreover, the N fertilization with a combination of 25% mineral and 50% slow release or 60-80% slow release significantly increased the yield and fruit quality compared to use the RDN only as a fast mineral release source. The promotion in the yield and fruit quality was associated with increasing the level of the slow release from 50 to 80% of RDN. Raising slow release used from 50 to 80% of RDN failed show any significant increase in fruiting traits. It is evident that fertilized with either 60% slow release or 25% mineral plus 50% slow release is very important for the grapevines production. It improves the nutrient status, yield and fruit quality of grapevines. In addition, it minimizes the production costs and environmental pollution which could be occurred with using fast release fertilizers.